Amazon has not yet signaled where its second headquarters will be located. But while Amazon execs continue to mull their headquarters options, the online retail behemoth is adding a fourth pick-up and returns center in the heart of the Chicago Loop business district.

Amazon said today its fourth location is now open at 203 N. LaSalle St. at the corner of Clark and Lake streets. The new outpost is manned by Amazon staff, but there are self-help kiosks at the new location, too.

Amazon's freestanding pick-up outlets offers at least one big benefit not available to customers who ship items to a home address. Amazon prime members can have any product shipped to a pick-up location with free same day delivery and no minimum order amount.

For same day delivery to a home or business address, Amazon Prime members typically must submit an order totaling at least $35 in merchandise that is tagged with same-day-delivery availability.

The new Amazon outlet in the Loop will be open seven days a week from 9 a.m. to 9 p.m. the company said. Orders will be kept at the pick-up outpost for up to 15 days.

Amazon's new Loop location is also equipped to handle returns. Customers can drop by the location and Amazon will provide a free shipping container to handle the return for the customer.

Amazon's other three pick-up locations are at University of Illinois at Chicago, as well as a location at Sheffield and Webster, and another at Clark and Diversey. Both of the latter locations are on the city's near north side.