The last four teams standing return to play in the UEFA Champions League this week for the first leg of the semifinals, when some of Europe's top sides will begin to map out their route to the final on May 31 at Munich's Allianz Arena.

As Barcelona prepare to host Inter in the Champions League semi-final first leg on Wednesday night, here is a look at some of the key battles that could influence the result between the two European

Germain, and Inter Milan entertain Europe and the world as the semi-finals of the Champions League begin. All four teams will be dreaming of booking their place in the final in Munich on May 31st.