US officials were "shocked" when they first saw the "extraordinarily unique" compound housing Osama bin Laden in "Pakistan's Sandhurst".
The relatively affluent area of Abbottabad, about 50 miles north of the capital Islamabad, houses retired military personnel and is away from the natural disasters and terrorist attacks that have hit other parts of the country.
But the $1m (€674,000) high-security compound stood out with its 12ft to 18ft walls and two security gates protecting a house roughly eight times larger than any others in the area, Obama administration officials said.
Built in 2005 at the end of what was then a narrow dirt road on the outskirts of the town centre, the main structure, a three-storey building, has few windows facing the outside of the compound.
Behind the barbed-wire-topped walls, internal walls sectioned off certain areas while a terrace on the third floor had an additional "7ft privacy wall".
"We were shocked by what we saw -- an extraordinarily unique compound," the officials said.
"The physical security measures of the compound are extraordinary."
While neighbours left their bins out to be collected, compound residents burned rubbish on site, the officials said.
And while the "courier" who aided Bin Laden -- who was linked to the property by US intelligence agents -- and his brother had "no explainable source of wealth", the property had no telephone or internet services associated with it.
"Intelligence analysts concluded that this compound was custom-built to hide someone of significance," the officials said. "Our best assessment . . . was that Bin Laden was living there with several family members, including his youngest wife.
"Everything we saw -- the extremely elaborate operational security, the brothers' background and their behaviour, and the location and the design of the compound itself, was consistent with what our experts expected Bin Laden's hideout to look like.
"Our analysts looked at this from every angle, considering carefully who other than Bin Laden could be at the compound.
"We had high confidence that a high-value target was being harboured and we assessed that there was a strong probability that that person was Osama bin Laden."