Complex sentence: The construction of the Montmartre funicular was decided by the Paris municipal council in 1891, to serve the Sacré-Coeur Basilica, built at the summit of the outlier of Montmartre and inaugurated 5 June 1891.
Split into simpler sentences: The construction of the Montmartre funicular was decided upon by the Paris municipal council in 1891. It was built to serve the Sacré-Coeur Basilica at the summit of the outlier of Montmartre and was inaugurated on 5 June 1891.