You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Doctor_Who

Context:
In 1993, for the franchise's 30th anniversary, another charity special, titled Dimensions in Time was produced for Children in Need, featuring all of the surviving actors who played the Doctor and a number of previous companions. It also featured a crossover with the soap opera EastEnders, the action taking place in the latter's Albert Square location and around Greenwich. The special was one of several special 3D programmes the BBC produced at the time, using a 3D system that made use of the Pulfrich effect requiring glasses with one darkened lens; the picture would look normal to those viewers who watched without the glasses.

Question:
What special was created for the show's 30th anniversary?

Dimensions in Time