"The entrance was in the North."
Translation:Der Eingang lag im Norden.
No. That does not work in German.
There is one kind of present tense in German:
Der Eingang liegt im Norden = "The entrance lies in the north" ("...is in the north")
This corresponds to both "The entrance lies in the north" and "The entrance is lying in the north", i.e. German has no separate form for the present continuous like English does. You cannot say something like '...ist liegt...'. Just no.
This also applies for the past tense. There are two types of normal past tense in German:
Der Eingang lag im Norden = "The entrance lay in the north" ("...was in the north")
Der Eingang hat im Norden gelegen = "The entrance has lain in the north" ("...has been in the north")
These two actually have the same meaning in German, although they are different in English. You cannot make a construction like you did.
There are ways to use war, but since you mis-conjugated "kann ich" I doubt the terms Plusquamperfekt or Partizip I mean much to you yet!
ist gelegen is passive voice, hat gelegen would be perfect as an alternative to preterite.
Thanks, I've amended it. Apparently the usage of sein as the helping verb is from southern dialects.