Eglin Air Force Base in Valparaiso, FL. Eglin Air Force Base in Valparaiso, FL Florida Military Bases Florida Military Bases. Elgin Air Force Base is a Untied States Air Force installation located in Okaloosa County, Florida. The 463, 128 acre base sits three miles from Valparaiso and Niceville. A short distance to the west lies the city of Fort Walton Beach.