Drift BnB is an awesome place to stay if you're planning on being in Colombo for a few days. It's located right off Galle Road (the main coastal road in Colombo) and is about a 5min. tuk-tuk ride from Galle Face Green (around 100-150 rupees) and a 7-8min. tuk-tuk ride to the Colombo Fort Train Station (200 rupees). There's not a whole lot in terms of monuments that you can walk to, but the transportation is cheap enough that you can reach pretty much every major sight in Colombo in under 10 minutes. There are, however, a lot of good bars and restaurants in the area, including the world-famous Barefoot Cafe, within a 5 minute walk.