Adam's Peak is the one to plan around, because it has a season. The pilgrimage months run from the December Poya to the Vesak Poya in May, when the steps are lit, the tea stalls are open, and thousands climb through the night. Outside that window the route is unlit and largely deserted — possible, and beautiful, but a different undertaking. We start you at around two in the morning to reach the summit before the sunrise crowd and the shadow the peak throws across the hills.
Horton Plains rewards an early start for a different reason: World's End is a 900-metre drop that mist erases most mornings by nine or ten. That means leaving Nuwara Eliya before six. The Knuckles range is the opposite kind of day — no crowds, no deadline, and paths through cloud forest and terraced villages that need a local guide because the trails are not signed.
Where you want more than walking, Kitulgala's rafting sits conveniently between Colombo and the hills, and the hill country's tea trails, waterfalls, and cycling around Polonnaruwa fill the softer days between the hard ones.