Selfoss is positioned at the hub of south Iceland's main attractions. The Golden Circle — Þingvellir, Geysir, and Gullfoss — lies to the north, with all three accessible in a full day. To the east, the volcano Hekla looms over the landscape; Landmannalaugar, the coloured rhyolite mountains and geothermal pools, is a few hours' drive on the F-roads (4WD required).
The south coast waterfalls are within easy reach: Seljalandsfoss, where you can walk behind the falling water, and Skógafoss further east. Þórsmörk, the mountain valley carved by three glaciers, is a classic Icelandic hiking destination about 90 minutes away; the river crossings require a 4WD or the highland bus in summer.
Strandarkirkja, a white church on a headland south of Selfoss, is a pilgrimage site revered by Icelandic sailors who promised to build a church there if they survived a storm; it is small but moving, and the coastline around it is wild and scenic.