Towel Day is celebrated every year on 25 May as a tribute to the author Douglas Adams by his fans. On this day, fans openly carry a towel with them, as described in Adams' The Hitchhiker's Guide to the Galaxy, to demonstrate their appreciation for the books and the author. (Source: Wikipedia) Location: STA Travel Cafe, Ajdovščina 1, 1000 Ljubljana Directions: When you arrive at the location, you have to go up the open-air staircase, as the bar is located upstairs.