Final answer:
The remains in London that signify the locations of the theaters that once existed include the modern Globe Theatre and reconstructed theaters like the Rose Theatre in Michigan. Additionally, remnants of Roman theaters can be found throughout Europe, Asia Minor, and North Africa.
Step-by-step explanation:
The remains in London that signify the locations of the theaters that once existed are a combination of original and reconstructed theaters. One significant remaining structure is the modern Globe Theatre, which is a reconstruction of the original Elizabethan theater. It was designed and built according to historical documents and features all the necessary modern amenities. Another example is the Rose Theatre in Michigan, a reconstruction of an Elizabethan theater. Additionally, there are remnants of Roman theaters scattered throughout Europe, Asia Minor, and North Africa, which provide insights into the theater's past.