Translation:The mountain that stands beside the famous city is high.
For your interest if you are confused whether you translate "magas" to high or tall: http://dictionary.cambridge.org/us/grammar/british-grammar/high-or-tall
Spoiler: A mountain can't be tall.
Spoiler: Actually, they can be.
Case and point: http://mentalfloss.com/article/90942/3-mountains-taller-everest "Three Mountains Taller Than Everest"