I am trying to wrap my head around all the different notions of dimension (and their equivalences). To get a sense of this, it would be nice to know the subtle difficulties that arise. I thus think it would be nice to have a list of such examples! (I dug through the internet without locating such a collection.)

This question/request can be interpreted as either

1) An example that obeys a particular definition of dimension but goes against our intuition. Said differently: an example that *should* obey a particular definition of dimension, but doesn't.

3) An example that disagrees with two different definitions of dimension.

4) An example which hinges on a hypothesis of the dimension.

*This last one is what got me to start this post, because I came across an example involving the Krull dimension: If our ring $R$ is Noetherian then $\dim R[x]=1+\dim R$, but if $R$ is not Noetherian then we can have $\dim R[x]=2+\dim R$. Found at http://www.jstor.org/stable/2373549?origin=crossref (The Dimension Sequence of a Commutative Ring, by Gilmer).

*I am not sure where our space-filling curves fit in here.

**Some standard definitions of dimension**

- Lebesgue covering dimension (of a topological space)
- Cohomological dimension (of a topological space)
- Hausdorff dimension (of a metric space)
- Krull dimension (of a ring or module)