Public restrooms are a rare commodity in Rome, and when found, they are often undesirable. Although there are public toilets in Piazza San Pietro, Piazza di Spagna, on the Palatine Hill, and in a few other strategic locations (often with a token service charge €0.50–€0.70), consider taking well-timed pit stops at a local bar. Most bars will allow you to use the restroom if you ask politely, though it is courteous to buy something such as a bottle of water or espresso—in exchange for access to the facilities. Standards of cleanliness and comfort vary greatly. Restaurants, hotels, department stores like La Rinascente and Coin, and McDonald's restaurants tend to have the cleanest restrooms. Pubs and bars rank among the worst. It's a good idea to carry a packet of tissues with you, as you can't rely on most places having any toilet paper at all. There are bathrooms in all museums, airports, train stations, and in most subway stations. In major train stations you'll also find well-kept pay toilets for €0.70. Carry a selection of coins, as some turnstiles do not give change. There are also facilities at highway rest stops and gas stations: a small tip to the cleaning person is always appreciated. There are no bathrooms in churches nor post offices.