剑桥火车站到剑桥主要景点的距离

在https://www.buytickets.northernrailway.co.uk/上购买去剑桥的火车票会有一个选项“£4.00 CAMBRIDGE+BUS www.plusbus.info/cambridge”，看介绍“For unlimited bus travel on participating operators' services around the whole urban area of your selected town(s), buy PLUSBUS ticket(s) from the options below. £4.00 around CAMBRIDGE STATION”应该是当天可以随便坐剑桥地区的公交，请问这个值得购买吗，从剑桥火车站到剑桥各主要景点距离很远吗？