This is the the 11th cache in the series of alphabet caches. The purpose of this cache is to eventually create a series of caches from A to Z. The next cache in the series is Alphabet L - Lord's House (NMS24) (GC8DC6) by Mesu &Helene.
NOTE! There's a new hiding place for the cache since 18.9.2010. The formulas have been updated accordingly.
The original coordinates of the cache might be needed for some later mysteries in the series. To get the original coordinates, make the following corrections to your calculations: N +0.011 E +0.132
To find this cache you need to visit the cache Alphabet J - Joys of Yachting (GCMACE) first. There you can find the values A and B.
The given coordinates are a reference point for a reference point. To calculate the reference point for the cache you need to study the image below. This image shows a well-known optical illusion that is often discussed in the Internet.
In the lower part of the image, there is clearly a white hole in the figure. Where does this hole come from? What color was this hole originally in the first picture?
The four pieces of the figure are blue, orange, red and green. Your task is to take the word representing the color that answers the above question and then calculate the sum of the letters in that word, where a=1, b=2... etc. Let that number be C.
The reference point for the cache is 10*C meters to the direction of 3*C degrees (true bearing) from the given coordinates. The distance to the cache is B-101 meters, and the true bearing to the cache is 0.9671*A degrees from the calculated reference point. 
To guarantee the continuity of the series, the following rules apply:
- The first finder of this cache must place a cache corresponding to the next letter in the alphabet within two weeks from the find. The cache must also be named like "Alphabet ? - ?...", where ? is the next letter and ?... is any name beginning with that letter.
- The next cache must be placed within the capital city region. That is, within the limits of Helsinki, Espoo, Vantaa or Kauniainen.
- The cache description must be constructed so that the cache can only be found by finding the previous alphabet cache. The preferred way is to write the final coordinates of the cache into the log book of the previous cache.
- These rules must apply also to the rest of the caches. Please copy these rules to the description.
Please don't rush yourself to be the first finder if you can't quickly put up the next cache. There are plenty of geocachers in the capital region who can.