The north entrance to the château is neat. You cross the moat (not currently watered) over a drawbridge. There are actually two spans. A main one for vehicles and a smaller one to the left for pedestrians.

The keep and donjon date to the 14th century. Henry V (Plantagenet) died here. The donjon is the tallest medieval fortification in Europe. It is supposed to be reopened to visitors in 2007. That means I didn't go inside.

This view of the châteua's north wall and tower is from near the subway entrance.  That is serious moat.

The Eiffel Tower is about 5 km from Montmarte. The damp air made things hazier (but helped capture the searchlight's beam).

Another long shot (2-4 km). The middle building with the golden dome is Les Invalides. The one below and to its right is the Assemblée Nationale. You can see the tricolor flying above its pediment. These two buildings are on the opposite side (left bank) of the river. The building to the left is the rear of the old Opéra (Palais Garnier).

Sacré Cœur was closed (or I couldn't find an open entrance). That's OK. I liked the outside views.

Sacré Cœur from the road below. The more interesting views are from the corners I think.

A closer (black and white) view from the corner angle.  Look!  Gargoyles!

A detail of Sacré Cœur.  I changed the white balance before this shot to get the warmer tint.