After your Geography degree at Durham you will be able to stay on in Durham City and do a Law conversion course. This will stand you in very good stead for a legal career.
In the years law conversion (at Durham and indeed anywhere) you study the 7 foundation subjects in law: tort, criminal, EU law blah blah and so on.
After that you will either proceed to do your LPC (Legal Practice Course) or go to do the BVC (Bar Vocational Course) if you want to be barrister - like me! So PM me if you wanna know anything about the Bar.
Career options are just as good and as wide as anyone who has done a normal law degree. Same in terms of salary. You actually stand out more for having done another degree prior to your law conversion, so all is good!