Get off Tokyo's circular Yamanote train line at Meguro station. Head out the west exit and walk along Meguro Dori for about 15 minutes, until you see an eight-story, brown brick tower topped with a silver sign that says MPM. The innocuous urban setting belies the horror show that awaits you within: MPM, you see, stands for Meguro Parasitological Museum, one of the most ghastly yet fascinating exhibitions you'll ever lay eyes upon. Though it occupies only two floors of a small office building, the museum boasts that it displays more specimens of roundworms, hookworms, flukes, nematodes and leeches than any other place on earthnot to mention gruesomely graphic images and descriptions of the havoc they can wreak on humans and other hosts. For sure, no one could possibly leave the museum complaining that there were too few of these creepy objects on show. The formaldehyde-filled glass jars of the often impressively large and malevolent-looking critters put the work of Damien Hirst to shame. Among the must-sees: a dog's heart with more holes than a wedge of Swiss cheese (thanks to a bad attack of heartworms); a tortoise's head with leech-ravaged eyelids; and an 8.8-m-long tapeworm extracted from a man who chose the wrong trout to eat raw. Even more weird, all of this is displayed with nonjudgmental cheeriness. The museum even has a gift shop filled with gaily colored, branded souvenirs certain to dumbfound or disgust the folks back home. Our favorite: a T shirt adorned with a menagerie of cartoon parasites and the slogan wonderful world of the worm.