Courtesy of Foreign Policy. Also the tip the broke the thing open:

In August 2010, the intelligence agencies found the exact compound where this courier was living, in Abbottabad, Pakistan. The neighborhood is affluent and many retired Pakistani military officials live there. 

"When we saw the compound where the brothers lived, we were shocked by what we saw," one official said. 

The compound was 8 times larger than the other homes around it. It was built in 2005 in an area that was secluded at that time. There were extraordinary security measures at the compound, including 12 to 18 foot walls topped with barbed wire. 

There were other suspicious indicators at the compound. Internal sections were walled off from the rest of the compound. There were two security gates. The residents burned their trash. The main building had few windows. 

The compound, despite being worth over $1 million, had no telephone or internet service. There's no way the courier and his brother could have afforded it, the official said.