Work crews completed the giant waterfront Rem Koolhaas (OMA) building in Rotterdam, the Netherlands on Thursday—16 years after the project started. De Rotterdam is slated to open early next year. Here are six facts to know.
1. Here's where Rotterdam is.

2. De Rotterdam really is a "vertical city." Check out these diagrams.

3. OMA's building is the biggest in the Netherlands, with 1,722,230 square feet of floor space.

4. That bridge in all of the pictures is the 1996 Erasmus Bridge, designed by UNStudio's Ben van Berkel. Its tower is 456 feet tall, just shy of Koolhaas' 492 feet (Although they probably don't start on the same sea-level.) This is the bridge in 2009.

5. About 85 percent of De Rotterdam's space has been rented or sold, despite criticism that it's a large building in a city with a large amount of vacancies.

6. It's been compared to Legos and the twin towers "resurrected in a Frankenstein muddle."

Update: This post originally misspelled the name of Ben van Berkel.