Complex sentence: There were 2 entrances to Eildon Mansion, one is still used by Eildon Mansion, the other is used by the next door property-they took ownership of this part of Eildon's property back in the late 1940s.
Split into simpler sentences: There were 2 entrances to Eildon Mansion, one is still used by Eildon Mansion, the other is used by the next door property. They took ownership of this part of Eildon's property back in the late 1940s.