Washington, D.C ? At night, the National Mall has an allure all its own, from the glow of the floodlit dome of the Capitol to the lights of the Washington Monument and Lincoln Memorial dancing off the Reflecting Pool.

But enticing as the Mall at night has become to locals and out-of-towners, it also has become more dangerous.

An outbreak of robberies and violent attacks has underscored an unpleasant reality that tourism officials would rather not acknowledge: The historic sites that make Washington a prime vacation destination are becoming rich hunting grounds for local criminals, especially after dark.

In the past month and a half, 12 people – 10 of them tourists – have been victims of armed robberies in the approximately seven-block stretch between the Washington Monument and the Smithsonian Arts and Industries Building. All of the incidents happened at night. Two of them involved sexual assaults.