Photo courtesy of Google Maps.

A recently-built Medford apartment building has sold for $23.12 million according to documents filed in the Middlesex South Registry of Deeds.

An affiliate of The Bulfinch Cos. bought 640 Boston Ave., in Ball Square near the Somerville/Medford line and a future Green Line Extension stop, from developer Dark Horse Capital Partners. The purchase was funded in part with $13.5 million in financing from Eastern Bank.

The 5-story Sphere luxury apartments were completed this year. Amenities include a top-floor residents’ lounge with a wet bar, roof deck, fitness center and indoor bike parking. The building offers both furnished and unfurnished rentals, as well as academic year-only leases. The unit mix includes one-bedroom and two bedroom-two bathroom units.