We don’t typically don’t think of national monuments as political hot potatoes.

But not every federally protected monument has been designated though consensus in Congress.

Presidents can –and have (many times)—invoked the use of the Antiquities Act of 1906 that gives the president wide sweeping powers to grant national monument status to areas of federal public lands that have significant historical, scenic, and/or scientific values.

President Obama Friday signed an executive order to incorporate Waco Mammoth Site into the national parks system (along with two scenic areas in California and Nevada) after Texas leaders failed to get the national designation through Congress.

AP: Students at the Waco Mammoth site in Texas.

Since the passage of the Antiquities Act, more than one hundred National Monuments have been designated.

Here are just a few worth visiting: