At each visitor’s site a marked trail provides excellent views of the wildlife, vegetation and landscape of Galápagos. Most trails are less than a mile long but a few can be fairly difficult underfoot, leading over rough lava or uneven boulders. There are also one or two longer hikes in the highlands. The different sites are amazingly varied in their scenery and vegetation, and the many good snorkeling spots offer the chance to see the varied underwater life of Galápagos. Certain animals are common at nearly every visitor’s site. These include sea lions, marine iguanas, lava lizards and a variety of coastal birds.