140 SQM Penthouse Office In Mosta. Cornerstone Business Centre is a prestigious office block located in the heart of Mosta’s commercial centre. Famous for its Church and Dome, Mosta and the nearby towns have a good stock of residential apartments that can be leased. There are also plenty of cafes and restaurants in the vicinity. The area currently available has an open-plan layout, with plenty of light, very large terrace with synthetic turf, and lovely views of Mdina, Mosta Bridge, and the iconic Mosta Church.