There are 12 marked hiking trails, with varying degrees of difficulty, on Mt. Parnitha.
Bafi Refuge. A 2.2-km (1.4-mile) ascent from the church of Ayia Triada (takes approximately 40 minutes) leads to the Bafi Refuge, run by the EOS Athinon (Hiking Club of Athens), where basic board and lodging are available. The refuge has a fireplace and kitchen; water is piped in from a nearby spring. The refuge remains open all year long. Parnithos Rd., Mt Parnitha, Attica, 13674. 210/240–3566; www.mpafi.gr.
Church of Ayios Petros. One of the milder, and most pleasant, hikes on Mt. Parnitha follows a marked trail from the church of Ayia Triada through the national park to the church of Ayios Petros at Mola forest. The path leads past the Skipiza spring, providing spectacular views of western Attica and the town of Thebes along the way. The 6-km (4-mile) walk takes about two hours, and you might spot deer darting among the trees. Mola forest, Off Parnithos Rd., Mt. Parnitha, Acharnés, Attica, 13673.
EOS Athinon Alpine Club. The Hiking Club of Athens runs huts where you can spend the night in the Bafi Refuge, and the organization can also give you information on the trails. In most cases, when you call you'll be able to find someone who speaks English. 210/321–2355; eosathinon.gr.
Flambouri Refuge. From Bafi, one trail turns south, tracing the fir and pine woods along the Houni ravine, skirting the craggy Flambouri peak—a favorite nesting place of the park's raptors. This trail intersects with another path leading to the Flambouri Refuge, a basic hikers' hut run by EOS Acharnon Hiking Club. You can stay the night or enjoy their views of Mt. Parnitha and hearty food, before exploring more trails. Off Parnithos Rd., Acharnés, Attica, 13674. 210/246–4666.