Spectrum is a pretty broad term. Do you have any area of interest you want to scan? E.g. Air, Amateur etc. Depending on your need, you can either get a standalone unit or software defined radios (like Hack RF). I don't have personal experience using Hack RF but I am pretty sure, with right antenna, it will do just fine.
You may want to look at this thread:
Traveling to Portugal
Also, if you are interested in ATC monitoring, here's a list of frequencies I found in liveatc.net site for Portugal:
Emergency/Guard: 121.500 MHz
LPHR (Horta) Approach: 120.600 MHz
LPLA (Terceira) Approach: 135.000 MHz
LPLA (Terceira) Tower: 122.100 MHz
LPPD (Ponta Delgada) Approach: 119.400 MHz
Ponta Delgada Ground: 131.600 MHz
Santa Maria Approach: 119.100 MHz
Santa Maria Control: 132.150 MHz
Note: I assumed you are in Portugal. You will get better location specific replies if you post in such forums.
