Investments in real estate properties are presented at cost, and consist of the following (in thousands):

		June 30,		December 31,
		2011 (1)		2010
Industrial portfolio (2):
	Improved land	$	5,035,181	$	2,527,972
	Buildings and improvements		17,594,674		8,186,827
Development portfolio, including cost of land (3)			632,196		365,362
Land (4)			2,033,725		1,533,611
Other real estate investments (5)			452,978		265,869
	Total investments in real estate properties		25,748,754		12,879,641
Less accumulated depreciation			1,764,289		1,595,678
Net investments in properties		$	23,984,465	$	11,283,963

(1) Included in the balances at June 30, 2011 are the real estate properties acquired in connection with the acquisition of PEPR and the Merger. See Note 2 for further details.

(2) At June 30, 2011 and December 31, 2010, we had 1,898 and 985 industrial properties consisting of 302.3 million square feet and 168.5 million square feet, respectively. Of the properties owned at June 30, 2011, 685 properties consisting of 81.1 million square feet were acquired in the Merger and 232 properties consisting of 53.0 million square feet were acquired in the PEPR acquisition.

(3) At June 30, 2011 the development portfolio consisted of 23 properties aggregating 8.6 million square feet under development and 5 properties aggregating 1.5 million square feet of pre-stabilized completed properties. Of these properties, 13 properties consisting of 3.7 million square feet were acquired in the Merger. At December 31, 2010, 14 properties aggregating 4.9 million square feet were under development. Our total expected investment upon completion of the development portfolio at June 30, 2011 was $1.1 billion, including land, development and leasing costs.

(4) Land consisted of 10,921 acres at June 30, 2011, of which 2,257 acres were acquired in the Merger, and 8,990 acres at December 31, 2010.

(5) Included in other investments are: (i) land subject to ground leases; (ii) parking lots; (iii) certain mixed-use properties and office buildings available for lease; (iv) our corporate office buildings, which we occupy; (v) certain infrastructure costs related to projects we are developing on behalf of others; (vi) costs incurred related to future development projects, including purchase options on land; and (vii) earnest money deposits associated with potential acquisitions.