Dictionary.com defines this word 'accoutrement' as: 1. An accessory item of equipment or dress. Often used in the plural.

2. Military equipment other than uniforms and weapons. Often used in the plural.

as well as (but with not much emphasis):

Outward forms of recognition; trappings: cathedral ceilings, heated swimming pools, and other accoutrements signaling great wealth.

The first two bring on visions of cannons and soldier statues in front of government buildings, while the latter is much closer to what I thought the word meant. I would use the word accoutrement in reference to Hearst Castle and JP Getty museum. Wouldn't you?