1. The National Postal Museum is a museum located in Washington DC that celebrates the history and impact of the United States Postal Service. Here are some interesting facts about the museum:

- The museum is home to the largest collection of stamps and philatelic materials in the world, with over 6 million objects in its collection.

- The museum’s centerpiece is a 90-foot-long mural called the \"Pony Express\" that depicts the famous mail delivery service in the American West.

- Visitors can see rare stamps, including one of the world’s most valuable stamps, the 1856 British Guiana One-Cent Magenta.

- The museum also has a collection of postal vehicles, including a stagecoach and a 1931 Ford Model A postal truck.

2. The National Postal Museum is open every day from 10:00 am to 5:30 pm, except for December 25. Their phone number is (202) 633-5555.

3. Admission to the National Postal Museum is free, but some special exhibits may have a fee. The museum is located at 2 Massachusetts Ave NE, Washington, DC, and is easily accessible by public transportation. The closest metro station is Union Station, and several bus lines stop nearby. Parking in the area is limited, so public transportation is recommended.