Arc de Triomphe
I went to the Arc de Triomphe deliberately at sunset, so I could see the city from high up both before dark and after. The Arc is not actually very tall and only took a few minutes to climb, but the views from the top were amazing. I could see everything: the Eiffel Tower, the Hotel des Invalides, the Parc Monceau, the tower of Montparnasse, La Défense, les Champs Elysées. I circled around for almost an hour before heading down.
A.G.
A view at night, along with lights on the Champs Elysées: