With the exception of that hideous g, I've always thought of Castle as an Optima wannabe.

Any reason it must be an Adobe font?

Monotype Grotesque has some similarities.

This kind of question is always tricky, because our idea of 'resemble' may be very different, but I would suggest looking at Lucida Sans, ITC Symbol (which is almost a sans) and ITC Eras which has a similar clean feel, and large x-height.

See if one of those is close enough to what you want.