Rwanda is a small landlocked country located in Central and East Africa. It has an area of 26,338 km2 and a population of over 12 million people. The terrain consists mainly of rolling hills, savannah grasslands, and tropical rainforests. The highest peak in Rwanda is Mount Karisimbi at 4507 meters (14,787 ft) above sea level. The climate is tropical with temperatures ranging from 10°C in July to 26°C in January. The area code for Rwanda is +250. This code is used when dialing from outside Rwanda to any other phone number within it. Additionally, to call a cell phone or landline inside Rwanda from another country you must dial 00 + 250 + telephone number. There are currently several area codes for different regions across Rwanda as all numbers are nine digits long starting with two numbers followed by seven numbers (e.g xx-xxxxxxx). Rwanda also has mobile networks which are operated by MTN and Airtel which use GSM networks with 3G/4G coverage available on all networks. To call a mobile device within Rwanda you must dial 00+250+ mobile network prefix + telephone number where the mobile network prefixes are either 7 or 8 depending on whether you are calling an MTN or Airtel device respectively for MTN and 8 or 6 depending on whether you are calling an Airtel device respectively for Airtel. Check physicscat for Rwanda in 2013.