Muslim Walls of Madrid Muslim Walls of Madrid The Muslim Walls of Madrid, also known as theArab Walls of Madrid, of which some vestiges remain, are located in the Spanish city of Madrid. They are probably the oldest construction extant in the city. They were built in the 9th century, during the Muslim domination of the Iberian Peninsula, on a promontory next to Manzanares river. They were part of a fortress around which developed the urban nucleus of Madrid. They were declared an Artistic-Historic Monument in 1954. The remains of utmost importance, with more archaeological than artistic interest, are in the Cuesta de la
1811–12 New Madrid earthquakes 1811–12 New Madrid earthquakes The 1811–12 New Madrid earthquakes were an intense intraplate earthquake series beginning with an initial earthquake of moment magnitude 7.5–7.9 on December 16, 1811, followed by a moment magnitude 7.4 aftershock on the same day. They remain the most powerful earthquakes to hit the contiguous United States east of the Rocky Mountains in recorded history. They, as well as the seismic zone of their occurrence, were named for the Mississippi River town of New Madrid, then part of the Louisiana Territory, now within the US state of Missouri. There are estimates that these stable continental region