The Madison Belvedere has been sold to Invesco for a client of the firm for about $300 million. The 50-story tower with 404 residential apartments at 10 E. 29th St. was developed by Rose Associates in 1998.

The building, by Fifth Avenue and Madison Square Park, was quietly marketed by Woody Heller’s team at Studley, which included Will Silverman, Eric Negrin and Daniel Parker.

No one would comment on the purchase price, which was revealed by other sources.

“It’s a great property and the tallest in the neighborhood, with very nice amenities, a well-appointed gym and an enormous roof garden,” said Heller.

Now in the hip NoMad area, it was more like No Man’s Land when the late Frederick P. Rose paid $11,598,792 to a convent for the site that is now home to the luxury tower.

Rose once bragged at a Silverstein Workshop at the NYU Real Estate Institute that he was pouring concrete at about a floor a week, having learned just-in-time engineering while in the Army.

His son, Adam R. Rose, is now co-president of the company, which is currently developing 70 Pine St., as Post colleague Steve Cuozzo reported.

The family builds large and well-appointed buildings to keep, and has previously sold only The Sheffield.

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Nearby, an iconic toy company is opening a retail store in an historical former toy building.

LEGO Systems has just leased 7,703 square feet at 200 Fifth Ave. on the prominent northwest corner of West 23rd Street for a flagship store that will open in January 2014.

The toy company is known for its colored blocks that combine into imaginative creations. It currently has a small outpost in Rockefeller Center and recently signed a lease to open at Ridge Hill in Westchester.

Jonathan Scibilia and Andrew Kahn of Cushman & Wakefield represented the toy tenant in the 10-year deal. David C. Berkey and Andrew Wiener of L&L Holdings represented ownership in-house. The asking rent was $500 per foot.

The 800,000-square-foot building was known as the International Toy Center for more than 75 years prior to its purchase in 2009 by L&L.

Led by David Levinson, L&L upgraded the building and the tenancies to include Grey Group, Tiffany & Co. and IMG Worldwide. Eataly is also a retail tenant and helped to transform the Madison Square Park area into a lively destination.

The Billund, Denmark-based LEGO Group was founded in the 1930s by Ole Kirk Christiansen and remains a privately held, family-owned company.

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Another kind of building block will soon take over at Pier 57 at the crossroads of Chelsea and Meatpacking District.

We’ve learned that by April, Youngwoo & Associates will be opening the P57 with 60 vendors in the head house using small shipping containers as storefronts.

Dubbed Incubox, and meant as an “incubator” for small retailers, the 20-foot by 8-foot containers will be rented for $3,000 on a month-to-month basis as the first step towards transforming the entire pier into a thriving destination.

When the entire pier opens in the spring of 2015, the developer expects established retailers will also rent them for pop-ups as well as more permanent stores.

At that time, an Incubox will rent for $5,500 per month with locations leased with the mere click of an on-line button, said Adam Zucker and Zachary Beloff of Youngwoo who were showing off a sample Incubox at the International Council of Shopping Centers event this week.

The finished P57 will have 240,000 square feet of retail and restaurant space over several levels with stores ranging in size from 1,000 to 50,000 square feet and up.

The Tribeca Film Festival will also take over the top deck of the pier with an amphitheater for its events.

Our favorite part, however, is a marketplace area where pieces of old airplane fuselages will be transformed into wide columns and double as food kiosks, performance spaces or spots for other activities.

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Yesterday, we trekked into the muddy Hudson Yards to join Related Cos. and partner Oxford Properties, along with MTA Chairman Joe Lhota and a few hundred other folks, including Mayor Mike Bloomberg, for an official groundbreaking ceremony for its first tower — and the only one that doesn’t first need an expensive platform built to get it above the trains.

Related Cos. CEO Stephen Ross said the 1.7-million-square-foot building at West 30th Street and Tenth Avenue is at this point 80 percent leased.

As we’ve reported, Coach will own its new offices there. Ross said two other term sheets have been signed for straight leases with companies that isources say are L’Oreal and SAP. Related is expected to sign a lease for the land with the MTA by June.

Before signage is set in stone, however, we think it is time to get the names of the new Hudson Boulevard and park changed to Bloomberg Boulevard to honor the legacy of the area’s biggest booster.

And while former Deputy Mayor Dan Doctoroff, who also attended the ceremony, didn’t succeed in getting a new stadium or the 2012 Olympics, he jump-started discussions over the use of the land, and we hope he is also honored at the site.