Las Grietas offers a diverse underwater landscape featuring a combination of reef, wall, and cave structures. Divers can explore depths reaching 20 metres, with visibility typically around 10 metres. The site is suited for intermediate divers due to variable currents that can intensify near the wall sections. Boat access is required to reach the site, where divers should remain vigilant regarding boat traffic during ascents and surface intervals. Proper line management is essential to avoid entanglement within the crevices and reef structures. On-site facilities include air fills, equipment rental, and changing rooms with showers.

Cala Illurgieta is a reef dive located in the Cantabric Sea near San Sebastian. The site features a reef structure that descends from 8 metres to a maximum depth of 24 metres. Navigation is manageable for beginners due to the mild currents present. Divers should note that visibility can vary between visits. Access to this site is by boat only, and guided tours are available to assist in locating smaller marine life on the reef surface. Given the water temperatures, which range from 12C to 20C throughout the year, a drysuit or a 7mm wetsuit is recommended for comfort.

Las Langostas is a deep wall dive in the Cantabric Sea, featuring a vertical drop that extends from 20 to 40 metres. Divers encounter moderate currents along the wall face, requiring precise buoyancy control and drift management. Due to the significant depth and potential for strong currents, this site is strictly for advanced divers. Access is exclusively by boat to avoid hazardous surf conditions near the shore. Water temperatures fluctuate between 12 and 18 degrees Celsius throughout the year. Divers should plan bottom times conservatively and carry a surface marker buoy to account for the current, which may push divers away from the wall during ascent.

Gran Cañon is a wall and reef dive located in the Cantabric Sea off San Sebastian. Reaching a maximum depth of 14 metres, this site is suitable for beginner divers looking to gain experience on vertical terrain. Access is by boat, and the site features a mild current. Visibility at Gran Cañon is variable, so it is advisable to check local conditions before planning a dive. Species recorded around this area include wrasses, common octopus, marbled electric ray, scorpionfish, conger eel, and various sea slugs and crustaceans. Divers should confirm appropriate wetsuit thickness with a local centre, as water temperatures fluctuate between 12 and 22 degrees Celsius throughout the year.

Ondartxo is a diverse marine site located in the Cantabric Sea off San Sebastian, Spain. The topography features a combination of reef, wall, and cave formations that descend from 14 to 32 metres, with an average depth of 18 metres. Access is exclusively by boat. Divers should be prepared for variable visibility and currents, requiring solid buoyancy control and navigation skills. Water temperatures range from 12C to 19C, necessitating appropriate thermal protection such as a drysuit or thick wetsuit. Due to the depth and potential for shifting conditions, this site is best suited for intermediate divers who can manage variable currents and monitor their depth profile carefully.

Bajo de las Gorgonias is a reef site located in San Sebastian, Spain, accessible only by boat. The reef structure extends from the surface to a maximum depth of 26 metres. Divers should be aware that visibility is variable and requires local verification before planning a trip. The site experiences mild currents, making it suitable for intermediate divers. Water temperatures fluctuate between 12C and 20C throughout the year, necessitating appropriate thermal protection. Species recorded around this area include wrasses, common octopus, conger eels, scorpionfish, slipper lobsters, and various nudibranchs. Due to the depth, divers must monitor their gauges closely to maintain a safe profile.

Astillero is a pinnacle located 500 metres offshore in the Cantabric Sea. The structure rises from a maximum depth of 27 metres to a shallow point of 5 metres. Divers and snorkellers can expect mild currents and visibility ranging from 10 to 20 metres. Due to the sharp drop-offs and significant depth, buoyancy control is essential. The site is accessible by boat and is suitable for beginners, with typical dives lasting around 40 minutes. Night diving is permitted at this location. Shore facilities available for visitors include parking, toilets, showers, changing rooms, a rinse station, air fills, equipment rental, and boat charter services.

Pikatxilla is a combined wall and wreck dive located in the Cantabric Sea near San Sebastian. The site features a vertical profile dropping from 3 to 32 metres, with an average depth of 25 metres. Divers encounter a mix of wall topography and wreck structures, which require caution due to entanglement risks. Conditions include mild currents and visibility ranging from 5 to 10 metres. Water temperatures fluctuate between 12C and 19C throughout the year, necessitating appropriate thermal protection. Given the depth and potential for variable visibility, this site is suited for intermediate divers. Boat access is required, and divers should monitor the sea state for surf conditions before entry.