Complex sentence: The square was created in 1979, with a large part of it being the former end of Grey's Avenue, which used to connect directly to Queen Street-a large underground carpark with 930 spaces had been erected underneath in 1975.
Split into simpler sentences: The square was created in 1979, with a large part of it being the former end of Grey's Avenue, which used to connect directly to Queen Street. Previously a large underground carpark with 930 spaces had been erected underneath in 1975.