Complex sentence: Historically in Hampshire, but today in Dorset, it is located to the east of Bournemouth town centre and west of Southbourne, It developed rapidly from a small village as a seaside resort alongside Bournemouth after the first Boscombe pier was opened in 1889.
Split into simpler sentences: Historically in Hampshire, but today in Dorset, it is located to the east of Bournemouth town centre and west of Southbourne. Boscombe developed rapidly from a small village into a seaside resort alongside Bournemouth after the first Boscombe pier was opened in 1889.