The German state Brandenburg, later Prussia, owned a colony at the Goldcoast, today’s Ghana, from 1683 to 1721.
Wikipedia has the best information on the subject. There is also a book about it, but currently only available in German. The book is available at amazon.com. An English translation has been finished. We are still looking for a publisher, contact Andreas-Martin Selignow at http://www.selignow.de for the rights.
The fortress is still there; some people reported that there is available accommodation. At the bottom of the fortress you will find Princes Town (or Princess/Prince’s Town), which has about 5,000 inhabitants.