Sigiriya

The spectacular rock fortress of Sigiriya is an impregnable fortress, a monastic retreat, and a rock art gallery.
Built in the 5th century AD to fend of a feared invasion, it is situated atop a 200m (656ft) high rock, and at the height of its glory must have been akin to a European chateau plonked on top of Ayers Rock.
There are water gardens, 5th century rock paintings of well endowed damsels, a 1000-year-old graffiti wall recording visitors impressions of the pin-ups, a couple of enormous stone lion paws and tremendous views.
To get to Sigiriya from Colombo, get in to a bus that stops at Dambulla, and from there catch any of the hourly buses going to the rock fortress, a total of 191km (118m).