Level 3's core business is wholesale communications services. The firm serves about 190 markets via its intercity network, which spans 67,000 miles in North America and 10,000 miles in Europe. It also owns metro networks in about 125 markets connecting to about 7,900 buildings, many the result of acquisitions over the past few years. The firm provides data transport, co-location, Internet access, and other telecom services. Level 3 also owns a small coal-mining operation.