Although not the easiest of sites to use, this does have the weight of the British Museums resources behind it. As a result, once you have got the hang of the timeline feature and the navigation, the interactive activities for students of history reward you with a wealth of knowledge and understanding about ancient civilisations.
Plus, click on "Staff Room" in the bottom left hand corner and a very useful teachers section appears. This section contains an overview of the interactive website, along with some very good history teaching resources and lesson plan materials. There is also guidance on lesson set up and planning using the website and an explanation of the educational goals of the site.