Known by several different names, including the American Society of Military History or the American Military Museum, Tankland is located in South El Monte near Los Angeles and Pasadena California, right next to the Whittier Narrows Recreation Area.
Naturally, enough, this is an outdoor museum that closes during bad weather, and it has limited hours relatively speaking. The museum is open to the public Friday, Saturday, and Sunday from 10:00AM to 4:30PM. They have tour booklets in English, Spanish, Traditional Chinese, Simplified Chinese, Korean, and Vietnamese.
Arrangements for vehicle or equipment rental, school tours, group tours, photo shoots, special event, birthday parties, or any other questions can be asked during office hours, which are Tuesday through Friday from 8:00AM to 4:00PM. Admission is $5 for adults which is a great price if you're into this sort of thing. They can only take cash, as an FYI but there are gas stations nearby with ATMs. Be aware that the entrance to the museum can come up a bit quick.
Presently, it's all American military vehicles, some in better shape than others. There's no throwing rocks, climbing on tanks, or smoking for a variety of good reasons and decorum.
They have a number of artillery pieces, a Police Rescue Vehicle with battering ram, jeeps, supply trucks from different eras and even an imitation of a Japanese tank used during the MGM film "Windtalkers."
They also have a UH-1B Huey helicopter which is handy if you want to get a good dramatic shot for whatever reason:
They're presently in the process of restoring a P61 "Black Widow" quad gun turret thanks to Steve Wagner, a 1950's M38A1C Jeep and 106mm Recoilless Rifle thanks to Mark Walter and Daniel French is restoring a 1940's Air Raid Siren.
Overall, I think you can spend a good half-hour to an hour looking at the various vehicles and getting an appreciation for what we put into use around the world. You can see how far we've come with some of our vehicles, and what technologies have remained difficult to improve upon.
The selection of vehicles reflects all of the branches of US military service, and they have a handy tour booklet you can take with you across the grounds if you want to read more about the specific pieces there. I wish them continued success and more support in the years ahead as we preserve and appreciate this aspect of our nation's history and the men who were a part of it.
As someone with an interest in the Secret War for Laos, I found it an enjoyable visit and would also pair this with a visit to the nearby March Field Air Museum, which is about an hour away. It's relatively easy to do both in a single day.