If yr gonna go moggymiaow, pick a *very* sunny, clear day - at least that way when you get to the site you'll have a really good view of Black Combe(I chose to go on a miserable rainy day and was highly unimpressed)

Like spaceship mark says, make sure you check out greycroft while you're in the area, also the awesome giant's grave is very close to Lacra and much more accessible!