The cluster of "treehouse" pensions on the road into the Olympos ruins is the place's calling card — a backpacker tradition since the 1990s, when a few small camps built simple wooden bungalows on stilts among the trees and started serving cheap dinners on long communal tables.
Many of the original camps still operate (Kadir's, Bayrams, Saban). The standard is rustic: thin walls, paper-flat mattresses, communal showers, three meals included for one rate. Don't expect romance or quiet — it's loud, social, and built for groups of 20-somethings. Go for the atmosphere, not the comfort, and stay in Çıralı if either of those is a deal-breaker.