TUNNEL ABSEILING PLUS tour the underground

History meets a real adrenaline rush. This 150-minute adventure in Zagreb County takes you into the 550-meter-long San Giovanni underground fortress, a partly unfinished World War II structure shaped by both construction and nature. You learn basic abseiling, descend natural rock with a rope, walk through concrete chambers, and finish with wine and an audio-visual presentation.

I especially like the gradual instruction and the small group of no more than eight people. You begin with equipment practice on level ground, so you are not simply pushed toward a cliff and told to hope for the best. I also like the way the fortress tour adds substance beyond the abseiling. The place has a forgotten, slightly eerie character that makes the activity feel more unusual than a standard outdoor rope course.

The main consideration is that non-slip footwear is mandatory, and the underground temperature stays around 14 to 16°C. The Plus version also includes a more demanding descent on uneven, slippery rock, so you should be comfortable with heights, confined spaces, and physical activity before booking.

Key points at a glance

• Three abseiling options: The standard descents are suitable for beginners, while Abseil Plus adds a cascading rock descent inside the fortress.
• A 550-meter underground fortress: San Giovanni combines unfinished military architecture, natural rock, special effects, and dark passageways.
• Small English-speaking groups: The group is limited to eight people, with professional certified instructors providing guidance and backup.
• A gradual introduction: You practice the technique horizontally before trying the vertical descent, which helps reduce first-timer nerves.
• Wine and a final presentation: The tour ends with an audio-visual surprise and a glass of wine, giving the activity a relaxed finish.
• Bring proper shoes and warm clothing: Hiking shoes or sturdy sneakers with non-slip soles are essential, not optional.

What makes the San Giovanni fortress unusual

San Giovanni is not a polished museum with glass cases and tidy labels. It is an unfinished World War II fortress, 550 meters long, with concrete rooms and natural rock forming part of the structure. That unfinished quality is the point. You see where military construction meets rough stone, rather than walking through a building that has been made uniform for modern use.

The facility was forgotten and hidden for years before being restored and prepared for visitors. That gives the tour a strong sense of discovery, but the site is not presented as a simple history walk. You come here to move through the building, use ropes, and experience the spaces from unusual angles.

I like that the historical setting is not treated as background decoration. As you pass through the fortress, the guides explain the site while special effects and projections add atmosphere. You get a story about the building, but you also get the physical feeling of its height, darkness, rock, and concrete.

The setting will appeal most to you if you prefer active sightseeing. If you only want a quiet underground tour, the rope work may feel like too much. For someone who wants a stronger memory than a standard guided walk provides, the combination is well judged.

Your first 20 minutes: instruction before action

Both the standard Abseil tour and Abseil Plus begin with an introduction to the equipment and basic technique. The operators provide all abseiling gear, and it is certified according to current standards and checked regularly.

You first practice on a horizontal surface. This matters because the rope system can feel unfamiliar even if you have climbed or hiked before. You learn how to handle the equipment and watch a demonstration of the descent before you leave the ground.

The instructors then help you get fitted out and explain the next step. The tour is designed for people without previous abseiling experience, and you can decide on the spot which descent feels right for you. That flexibility is one of the best features here. You do not have to commit to the hardest option before you understand how your body reacts to the height and equipment.

The staff also provide backup and direct support during the descents. Reports from recent bookings specifically praise Sara and Marko for being patient, friendly, and clear in their explanations. That is useful information for a beginner. You want instructors who can slow down, repeat a step, and keep the mood calm when your feet are on a vertical rock face.

The first descent: a good test for beginners

The easier abseiling option involves walking down a vertical rock surface while supported by the rope. This is not a free fall. You control your movement with instruction and safety equipment, while the guide provides backup.

For a first attempt, the walking descent gives you time to understand the basic body position and the sensation of moving backward over an edge. You can work out how much pressure to place on your feet and how to trust the system. The experience still provides an adrenaline rush, but it does not demand the same confidence as a jump.

You may then repeat the descent in a slightly harder form, using a vertical jump. Both versions are intended for beginners, but that does not mean they feel effortless. Heights can make simple instructions seem complicated, especially when you are looking down instead of at the guide.

I recommend treating the first descent as a skills session rather than a test of courage. Listen carefully, take your time, and use the chance to build a feel for the rope. The format allows you to gain confidence step by step instead of trying to impress the rest of the group.

Why Abseil Plus costs more in effort, not just time

The Abseil Plus tour includes the first two descents and adds another abseil inside the fortress. This third descent follows a cascading rock surface, which is more uneven and can be slippery.

That change is important. A smooth vertical face lets you focus mainly on height and rope technique. Uneven rock asks you to place your feet more carefully and adjust your body as the surface changes. You should expect the Plus option to feel more physical and less predictable.

The earlier descents act as preparation. By the time you reach the cascading rock, you have already practiced the equipment and basic movement with instructor support. You can also decide based on your comfort level during the tour. If you are nervous at the start, the gradual format gives you a fair chance to see how you feel before attempting the most demanding section.

Abseil Plus also offers the chance for two people to abseil simultaneously. That can add a social element, although you should choose it only if you feel comfortable with the technique and the guide confirms it is suitable for your group.

At $88 per person, the Plus version has reasonable value if you want both the fortress visit and several rope descents. You are paying for certified equipment, professional instruction, entry, insurance, special effects, transport back to the starting point, and the wine tasting. It is not a cheap sightseeing ticket, but it offers more active time and support than a basic underground walk.

Inside the two-level fortress

Once you complete the outdoor or natural-rock descent, you enter the high underground rooms built in concrete. The fortress was made on two levels, so the route has a sense of vertical movement rather than being one flat corridor.

The change from natural rock to concrete is part of the appeal. You see how the unfinished structure uses the site itself, and the scale of the rooms helps you understand why the building is more than a small tunnel. Special effects accompany the walk, and projections help connect the atmosphere to the fortress’s past.

You should not expect a conventional military museum filled with detailed displays. The value here comes from the setting and the way the guides bring it to life. The underground rooms can feel eerie, especially when the lights are reduced. One recent booking described the bunker as unsettling in places, particularly in the dark, but still worthwhile as an unusual experience.

That darkness is used carefully as a final challenge. The bravest members of the group can turn off their head torches and try to find the way out in pitch darkness. This is optional, and it is not the part to force if confined spaces make you uncomfortable.

The final audio-visual presentation and wine

The tour ends with a special audio-visual presentation designed to take you back in time. It gives the activity a calmer closing moment after the ropes, dark rooms, and physical movement.

A glass of wine follows, with time for conversation. I like this ending because it lets the group come down from the adrenaline instead of simply being sent back to the meeting point. It also gives you a chance to talk with the guides and other participants about the fortress and the descents.

Wine is included, but you should not drink before the activity. The agency can refuse participation if someone arrives under the influence of alcohol or drugs. That is both a practical rule and a sensible safety measure for a rope-based tour.

Recent feedback also highlights the presentation and wine as a pleasant finishing touch. One person described the experience as a good way to end a holiday, which makes sense. The tour has enough physical excitement to feel special, but the final social moment keeps it from becoming only a high-energy stunt.

Safety, comfort, and who should book

The tour is suitable for beginners, but beginner-friendly does not mean suitable for everyone. You should be comfortable with heights and able to manage an underground setting. The operator specifically advises against booking if you have claustrophobia or epilepsy.

Children under 10 cannot participate. The tour is also not a good choice if you dislike uneven surfaces, rope equipment, or the idea of moving through dark enclosed spaces.

Wear hiking shoes or sturdy sports shoes with non-slip soles. This is the most important packing detail. Smooth-soled trainers are not enough, particularly for the cascading rock section. Bring a warmer layer as well, since underground temperatures range from 14 to 16°C. You may feel warm during the active parts, but the fortress itself remains cool.

The agency may adjust the tour because of bad weather. It may also change the activity if your footwear is inadequate. Tours and entry into the underground facilities are taken at your own risk, so follow the guide’s instructions closely.

The small group limit of eight is another safety advantage. You receive more direct attention than you would in a large commercial group, and the instructors can keep track of each person’s comfort and progress.

How the $88 price compares with the experience

At $88, this is a mid-priced adventure rather than a simple attraction. The price makes more sense when you count what is included: guided entry to San Giovanni, all abseiling equipment, certified instructors, insurance, audio-visual effects, the return ride in an air-conditioned van, and wine tasting.

The tour lasts about 150 minutes, so you get roughly two and a half hours of instruction, activity, underground exploration, and social time. That is a solid block of time for a small-group experience.

I would consider it good value if you want something active and unusual, especially if you have already seen more traditional historic sites. It is less suitable value if you are mainly interested in the fortress itself and have no wish to abseil. In that case, the operator also offers a no-abseiling underground tour.

Free cancellation up to 24 hours before the start and reserve-now, pay-later booking give you useful flexibility. Private tours and other dates or times can be arranged directly with the operator through WhatsApp at +385 98 316 322.

Book it if you want history with a pulse

I would book TUNNEL ABSEILING PLUS if you want a small-group activity that combines local history, underground architecture, and a manageable physical challenge. It is especially well suited to first-time abseilers who appreciate patient instruction and the option to choose their difficulty as they go.

Choose the standard Abseil tour instead if you are unsure about the slippery cascading rock or do not need the extra descent. Choose the Plus version if you want more rope time, a stronger challenge, and the possibility of abseiling in pairs.

You should skip it if you have claustrophobia, epilepsy, are under 10, or do not have sturdy non-slip footwear. For everyone else, the best reason to book is the unusual mix: you learn something about a forgotten fortress, test yourself on natural rock, walk through darkness, and finish with wine rather than a hurried exit.

FAQ

Where does the TUNNEL ABSEILING PLUS tour take place?

The tour takes place in Zagreb County, Croatia, at the underground San Giovanni World War II fortress.

How long does the tour last?

The activity lasts 150 minutes, or about two and a half hours.

How much does the tour cost?

The listed price is $88 per person.

Is previous abseiling experience required?

No. The descents are designed for beginners, and professional instructors provide instruction, guidance, and backup.

What is included in the price?

The price includes certified abseiling equipment, a guided tour and entrance to San Giovanni fortress, professional certified guides, insurance, audio-visual effects and projection, and wine tasting.

How many people are in each group?

The tour is offered in a small group limited to eight participants.

What should I wear?

Wear hiking shoes or sturdy sports shoes with non-slip soles, and bring warmer clothing because the underground temperature is about 14 to 16°C.

Is the Plus descent harder than the standard descent?

Yes. Abseil Plus adds a descent on cascading rock inside the fortress. The surface is uneven and can be slippery, making this section more demanding.

Can I choose my abseiling difficulty?

Yes. You can decide on the spot which descent you want to attempt based on your comfort level. The standard options include a walking descent and a slightly harder vertical jump.

Who cannot join the tour?

The activity is not suitable for children under 10, people with claustrophobia, or people with epilepsy. The agency can also adjust or refuse participation if someone has inadequate footwear or is under the influence of alcohol or drugs.