Sacré-Cœur Basilica

Sacré-Cœur was built as a national vow of penance after France's crushing defeat in the 1870 Franco-Prussian War and the bloody suppression of the Paris Commune. The Third Republic hated the whole project as a reactionary Catholic imposition on secular republican France — but the vow had already been made, funds raised by public subscription, and the site chosen atop Montmartre where the Communards had been executed. Construction ran from 1875 to 1914 (and consecration was delayed until 1919 by WWI).

The white travertine of the exterior is not paint — it's a self-cleaning stone from the Château-Landon quarry that secretes calcite when it rains, which is why the basilica always looks freshly washed. The interior is dim and cavernous, dominated by the massive golden mosaic of Christ in the apse (Christ in Majesty by Luc-Olivier Merson, 1922, one of the largest mosaics in the world). Adoration of the Blessed Sacrament has been continuous here since 1885 — a monk or nun is always present in the crypt praying.

The view from the steps is one of Paris's essentials — all of central Paris laid out below with no high-rises to interrupt the sight lines. Entry to the basilica is free. The dome (€8, 300 steps up a narrow spiral) gets you the same view but higher and quieter; worth it on a clear day.

Approach Sacré-Cœur via the funicular from Anvers metro (uses a normal metro ticket) or walk up the stairs from Place Saint-Pierre. Skip the crowds on the front steps and head to the west-facing terrace behind the basilica for sunset — same view, fewer people.