Stormy Skies at Castillo de San Cristóbal
A broad panoramic view of Castillo de San Cristóbal at San Juan National Historic Site. Designed by the Irish-born engineer Thomas O'Daly, this fortress is the biggest European fortification in the Americas. Here one can see a sentry box, which was occupied by soldiers on lookout. To the right a ramp ascends to a higher tier of the fortress. Dark clouds loom in the distance.