Lego first began back in the 1930s and is undoubtedly one of the most enduring children's toys to date, but who are we kidding, the grown ups love it too. So much so that this series has been trying to find the UK and Ireland's best Lego builders with some of the most skilled brick fanatics doing battle to be crowned Lego Masters. In tonight's episode, the five remaining teams take their construction skills into the great outdoors to complete two challenges on the theme of nature. First, they have to create and install a brick display for a nature walk that will be transported to a woodland in Essex. There is also a quick fire round to make as many miniature creatures as they can in 45 minutes, using no more than 15 bricks each. Presenter Melvin Odoom and judge Matthew Ashton are joined by two guest judges - comedian Bill Bailey and leading brick artist Sean Kenney.