Property

Our property consisted of the following (in thousands):



	December 31,
	2016		2015
Land	$	1,107,072	$	929,958
Land held for development	82,953		95,524
Land under development	51,761		17,367
Buildings and improvements	3,489,685		3,152,215
Construction in-progress	57,674		67,895
Total	$	4,789,145	$	4,262,959

During the year ended December 31, 2016, we sold 12 centers and other property. Aggregate gross sales proceeds from these transactions approximated $241.9 million and generated gains of approximately $100.7 million. Also, during the year ended December 31, 2016, we acquired three centers and other property with an aggregate gross purchase price of approximately $464.6 million, which included the consolidation of a property from the acquisition of a partner's 50% interest in an unconsolidated tenancy-in-common arrangement, and we invested $63.3 million in new development projects. Also during 2016, property increased by $58.7 million as a result of a business combination. See Note 23 for additional information.

At December 31, 2016, one center, totaling $1.6 million before accumulated depreciation, was classified as held for sale. At December 31, 2015, one center, totaling $53.2 million before accumulated depreciation, was classified as held for sale. Neither of these centers qualified to be reported as discontinued operations, and each was sold subsequent to the applicable reporting period.