Prepositions for PPs including the NP (etc) "placement" or "clinical placement"

Which of these is correct?

• I went to the cardiac ward in my first clinical placement.
• I went to the cardiac ward for my first clinical placement.
• I went to the cardiac ward on my first clinical placement.

Also, is it better to say I went in or I went to?

If this was just describing a past event to a friend, for example, the second would be a good choice:

• I went to cardiac ward for my first clinical placement.

It still needs so work, as 'ward' is a count noun and if left without an article or anything will default to the uncount noun:

• to the cardiac ward

Finally, 'went' is rather a single-use verb, it lacks the feeling of a repeated action. So we could use a different ploy:

I was on the cardiac ward for my....