Leonidio has been developed to be a limestone sport climbing paradise. Most sectors are generously bolted, with routes sometimes tightly spaced. Many routes terminate at 35 meters to make it easy to complete with a 70 meter rope. A few sectors have routes up to 40 meters. In those cases an 80 meter rope is needed (or two ropes). We had only 70 meter ropes and had no problems. It is not uncommon to have 13 to 15 bolts on a 30-35 meter route. The first two or three bolts are usually closely spaced and very close to the ground. It is common for routes to have extensions - one set of anchors, and then another set of anchors higher up. Usually an extension involves 3 to 5 more bolts, and has harder climbing than the lower part of the route. The style of anchors varies from sector to sector. Most are rings, but some have carabiners or hooks to make the lower off more convenient.
The climbing in Leonidio spans the grades from 5a to 8c+ (5.6 to 5.14+). Anyone who climbs consistently at 6a (5.10a) or above will have hundreds of routes to choose from. Some newer guides to Leonidio have upgraded the ratings of many routes from the local guidebook. We found the ratings to be pretty consistent with the USA, although for many new routes the ratings were inconsistent. Rock quality is mostly very good, but there are plenty of new sectors with some loose rock, and some routes with very sharp rock and holds.
Here is some beta on a few other sectors we frequented. We climb at a moderate level (6c+ and below / 5.11 and below). This list represents only a small portion of the climbing in Leonidio. New sectors are constantly in development, typically 150+ new routes every year. The potential for new crags and long routes in the valley is mind boggling. The website Climb In Leonidio keeps a fairly up to date list of sectors and routes. The site also has other general info that will be helpful.
Aresos. A very nice sector with some high quality route in the 6b range. This sector has only 12 routes now, but has a good view, a nice, roomy spot to hang out, and high quality rock. Several of the routes have extensions. The best routes here are Terpnon, Agroktima and Vervesos. All three are about 6b, and have steep, pumpy climbing for the grade, and excellent rock.
Dornroschen. Twenty plus routes on a wall that gets early morning shade, and afternoon sun. Easy approach and mostly very good rock. Some routes here are thin slabs with small holds, while others are steep and full of jugs. Good variety. A favorite route here was Nichts Its Mal Eben - steep climbing on an exposed arete (6b).
Douvari. This sector is on the rock directly above town, and is reached by a steep hike leaving from the center of town. Expect to hike uphill for 20-25 minutes. A very popular sector for it's high density of fairly easy routes, and general good quality. Many routes have long extensions that add steepness and difficulty - so it's easy to climb here with people of variable ability. Routes here are closely spaced (sometimes only a few feet apart) and very well bolted.
Elona. High up in the Dafnon river valley, about 30 minutes drive from Leonidio is this crag and the adjacent Elona Monastery. Don't miss it, well worth a visit. This is a higher, cooler, mostly shady crag, great for warm days. Mostly very steep and high grade routes (7a to 8c+).
Frydi. This small crag is located along the road to the Saint Nicolas Monastery. The rock looks great, but we found this to be the most disappointing crag in Leonidio. The routes are mostly contrived, with odd bolt placements, and not very enjoyable climbing. Do yourself a favor and skip this crag.
King of Thrones. A cool, shady wall great for warm days. You could climb at Dornroschen (which is directly along the approach just a few minutes before this crag) in the early morning, then move here later for a full day in the shade. Good, steep routes here from about 6b to 7c.
Orama. This crag was developed in 2016 and was still undergoing some development when we visited. The trails to the routes are new, and some still need some work. But the rock quality is superb and the number of quality routes in a small space is amazing. About 40 routes here (mostly 6a to 7a), plus extensions. This wall faces south, and is best for cool or shady days. Many routes here are a considered a bit underrated in the original 2016 guidebook, and have been upgraded in a more recent Greek guidebook. A few of the superb quality routes include Nightfall (6b), Marauder (6b) and Kapari (now given 6b+).
Mad Wall. A very good quality wall with many moderate routes. Fairly easy approach and good view of the sea. Generally very warm and sunny. About 20+ routes, mostly 5b to 6b+. A couple of good flat spots to hang out underneath olive trees. Check out B2, Aerostato, Koukoutsi, Tsibouki, I am a Hero and Don't Panic. All good routes in the 6a to 6b+range.
Mars. Probably our favorite crag in Leonidio. A 30 minute hike to a relatively remote location, gets you to this fantastic crag. Gorgeous tufas, superb rock, and even more superb climbing. The crag has morning sun and afternoon shade and can be crowded. Routes are from 6b and up. Many are quite long and steep. All the routes we did were excellent. The left side of the crag is smoother, less steep and is without tufas, but still superb quality. If you have time, plan to spend at least a few days here.
Rocspot. This crag is located above town, directly between the Orama and Douvari sectors. About 20 mostly high quality routes on excellent red limestone. Primarily 6a to 7a.
Sabaton. A new sector located on the road out of town towards Athens. It is still close to town and has super easy access and all day shade. In late 2017 there were 57 routes. Some are excellent quality - some not so good. Many routes are still cleaning up and will likely be even better in the future. Well worth a couple fo visits.
Saint Nicolas. This is a striking and beautiful valley located above town, and home to another spectacular monastery. The most striking thing about this valley is the road and drive up to the climbing. The road here is exceptionally steep, narrow and exposed. Not a drive for the faint of heart. It can be negotiated in a normal, small car, but you had best be very comfortable with a manual transmission on a very steep road. Once you arrive, there is plenty of parking at the monastery. The valley has climbs on both sides of the canyon, and is a beautiful locale. We had troubles with the many goats in the valley kicking off loose rocks from above the cliffs. Beware and wear a helmet. Some great routes we sampled were Tado (6b) and Mono-ton (6c+).
Skiadhianiko. An excellent crag located up canyon, below Elona. This crag has a nice approach trail and has a good variety of routes - steep, long routes and short slabby routes. Very good quality rock.
Twin Caves. Located well above town on the road to Vaskina, the Twin Caves are another favorite. To the left of the caves is a wall with about a dozen excellent routes from 5c to 7a. The super classic Avgi (6b+) was our favorite. Also good were Gumbo, Tsibouri and Nanaki. The main cave features another 20+ steep and gorgeous looking routes, mainly 7a to 8b+.