Translation of cruel in German

In the end we went up to the tower. We have never climbed so steep stairs ever before and once up we were really afraid to go down. There were no safety installation at this tower.
People on the bikes continued to drive around us although we were in the middle of the street. Supposedly this city has more than ten million inhabitants and more than three million bikes.
Many thanks for your letter. I am delighted to tell you that I have passed my exams and am looking forward to the next year. Meanwhile I am planning a trip to Costa Rica and some places around there.