Philadelphia

If you ever need reminding that Mexico City is one of the largest metropolises in the world, try taking the subway. Whenever I did, most of the population seemed to want to squeeze on to the same train. As a local put it, "For two pesos you get transportation, sauna and massage."

Speaking of saunas, when Thomas Jefferson & co were debating the finer points of the Declaration of Independence in the summer of 1776 the delegates complained about the sweltering temperature. Well, nothing much has changed in Philadelphia in the last two centuries. We're currently experiencing such an extreme heatwave that school students are being sent home early because the buildings don't have any air-conditioning. Fortunately, there's cool air in the museums and my hotel room.

I've continued my artistic pilgrimage with visits to the magnificent Philadelphia Museum of Art and the delightful Pennsylvania Academy of the Arts. But I'm also throwing in a few offbeat museums, such as the Mütter Museum at the College of Physicians. This little gem features more specimens of anatomical deformities than you would ever believe, from skeletons of two heads with one body to one head with two bodies. Gloriously gruesome stuff. And I'm not sure which terrified me more: a display of instruments of torture at the Inquisition museum in Mexico City or the medical instruments to assist with childbirth at the Mütter.