Best-Lock Construction Toys is a brand of plastic building bricks that are compatible with Lego.
 Best-Lock Ltd is based in Colne, Lancashire, England.
Mettoy Playcraft Ltd was the name of a range of toys manufactured in Northampton and Fforestfach Swansea, between the 1930s and 1980s.
 The Mettoy (Metal Toy) company was founded in 1933 by German émigré Philip Ullmann and was later joined by South African-born German Arthur Katz who had previously worked for Ulmann at his toy company Tipp and Co of Nuremberg.
 The firm made a variety of lithographed metal wind-up toys. Both Jewish, they moved to Britain following Hitler’s rise to power in 1933.
 The firm is most famous for its line of die-cast toy motor vehicles of their Corgi Toys branch created in 1956.
 In the same year Mettoy merged with the Playcraft model railway and slot car company.
Nanoblock (Japanese: ナノブロック , Hepburn: Nanoburokku ) is a line of construction toys manufactured by Kawada Co. Ltd, a toy company based in Tokyo, Japan.
Cubelets are a line of construction toys manufactured by Modular Robotics.
Toobers & Zots are creative construction toys which were invented in the 1990s by Boston-area based sculptor Arthur Ganson.
 They were manufactured by Hands-On Toys.
 Toobers & Zots consist of long flexible foam pieces called "toobers" and flat foam pieces called "zots."
 Toobers range in size from two to four feet long, so they are great for creating large scale objects.
 Zots come in various shapes and sizes and they are used to decorate the toobers.
 Although they have not experienced the critical or commercial success of such toys as the LEGO building blocks or Tinkertoys, they were highly successful in the specialty market and were very popular amongst educators and art communities.
Pawparazzi is a line of collectible, miniature plush toys manufactured by Noodle Head, Inc.
 The toys are similar to other plush toys; however each pet has a celebrity personality promoted in a gossip magazine and on an interactive website dedicated to the pets.
 Each pet comes with a purse designed to mimic the celebrity trend of carrying pets in purse-style pet carriers.
Integrity Toys is a toy company that designs and markets fashion and celebrity dolls and related accessories, with a focus on high-end fashion dolls. Integrity Toys was founded in 1995 by Percy Newsum.
 Integrity Toys is a privately held company located at 100 Chestnut Springs Road in Chesapeake City, Maryland.
The History of Lego began in 1932 in a Danish carpentry workshop and continues into the 21st century as a popular and very profitable line of construction toys and related products and services, including Lego board games, retail stores, Lego video games, Lego films, Legoland theme parks, and Lego Serious Play consultant services, with a significant impact on various areas of popular culture.
 Despite its expansion, the company remains privately held.
Lego (] ; stylized as LEGO) is a line of plastic construction toys that are manufactured by The Lego Group, a privately held company based in Billund, Denmark.
 The company's flagship product, Lego, consists of colourful interlocking plastic bricks accompanying an array of gears, figurines called minifigures, and various other parts.
 Lego pieces can be assembled and connected in many ways, to construct objects; vehicles, buildings, and working robots.
 Anything constructed can then be taken apart again, and the pieces used to make other objects.
Tente was a line of construction toys created in 1972 by EXIN-LINES BROS S.A., a plastics and toy company based in Barcelona, Spain which ceased operation in 1993.
 Subsequently, the trademark and patents were acquired by EDUCA BORRAS, and as of 2008 the toy line appears to be discontinued.
 Their later series were no longer compatible with the old system, although some models remained compatible.
 The toys consisted of multi-colored interlocking plastic bricks in multiple scales and an accompanying array of wheels, minifigures, and various accessories.

Question: Best-Lock Construction Toys are compatible with a line of construction toys manufactured by a privately held company based out of where?
Answer: Billund, Denmark