It's also relatively easy for English speakers to navigate; most people speak English and most tourist-oriented websites have an English option.
Agree that The Netherlands is a good choice; its size means you can easily mix time in cities with time in nature. Amsterdam is a good starting point for museums, art, and gay culture; De Hoge Veluwe National Park is a good place to experience nature (and has a large art museum located inside); and there are lots of other cities for day-tripping, like Utrecht, Rotterdam, and Den Haag. The cities are pretty safe as long as you practice basic city awareness and pickpocket avoidance. It's also relatively easy for English speakers to navigate; most people speak English and most tourist-oriented websites have an English option.