To get there, find Sultanhamet on the map, and take the highway there. Take one of the smaller roads up, until you reach a road going the opposite direction. Explore the roads near the word Sultanhamet on the map. You will find a large, gray building with many windows and a door as shown in the picture. Enter it.
Timmy Vermicelli is in here. To find him, go down the stairs. When you get to the bottom, you shall see a red part of wall with an opening. Timmy is here, which is the real purpose of why the building is accessible. In here, however, there are many sinks, but there are also green floors, red walls, and more.