1 calorie of heat is the amount needed to raise 1 gram of water 1 degree Centigrade. 1 calorie (cal) = 4.184 J. (The Calories in food ratings are actually kilocalories.) A BTU (British Thermal Unit) is the amount of heat necessary to raise one pound of water by 1 degree Farenheit (F). 1 British Thermal Unit (BTU) = 1055 J (The Mechanical Equivalent of Heat Relation) 1 BTU = 252 cal = 1.055 kJ.
San Antonio River Walk. A couple strolls along the River Walk. The San Antonio River Walk (also known as Paseo del RÃ­o or simply as the River Walk) is a network of walkways along the banks of the San Antonio River, one story beneath the streets of San Antonio, Texas, USA.
Must see in San Antonio. The Alamo is San Antonio's best-known attraction and shouldn't be missed due to its important role in Texas history. Visitors should also trek along the River Walk, a five-mile stretch of walkways following a river flanked by fun shops, restaurants and bars serving Texas-sized margaritas.