TRY THIS :)
mysql code.... simple one
select CITY,LENGTH(CITY) from STATION order by Length(CITY) asc, CITY limit 1;
select CITY,LENGTH(CITY) from STATION order by Length(CITY) desc, CITY limit 1;
Edit:
The above solution is not working for me as it doesn't sort alphabetically. As commented by @omotto
the following is the proper way to make it work. I have tried in SQL server and it works.
select top 1 city, len(city) from station order by len(city) ASC, city ASC;
select top 1 city, len(city) from station order by len(city) DESC, city ASC;