Narrative:

The day's flight began from ZZZ2 airport to ZZZ3 airport. At ZZZ3 I decided to go to ZZZ airport before returning home. While flying to ZZZ at 5500 ft MSL, ZZZ1 appeared on the argus moving map. I deviated south to avoid that area, passing about 2 miles south of said area. After contacting ZZZ tower giving my intentions to land they asked me to identify, which I did. After landing, they gave me a number to call contacting ZZZ4 center. After calling center, I was asked identification information, which I answered. Then they told me I violated ZZZ1 extended airspace. I did not realize ZZZ1 had extended airspace. I probably should have called FSS, but it was such a nice day, I didn't really feel it was necessary.

Google
 

Original NASA ASRS Text

Title: AN SMA PLT VIOLATED A TFR INVOLVING RESTR AIRSPACE.

Narrative: THE DAY'S FLT BEGAN FROM ZZZ2 ARPT TO ZZZ3 ARPT. AT ZZZ3 I DECIDED TO GO TO ZZZ ARPT BEFORE RETURNING HOME. WHILE FLYING TO ZZZ AT 5500 FT MSL, ZZZ1 APPEARED ON THE ARGUS MOVING MAP. I DEVIATED S TO AVOID THAT AREA, PASSING ABOUT 2 MILES S OF SAID AREA. AFTER CONTACTING ZZZ TWR GIVING MY INTENTIONS TO LAND THEY ASKED ME TO IDENTIFY, WHICH I DID. AFTER LNDG, THEY GAVE ME A NUMBER TO CALL CONTACTING ZZZ4 CTR. AFTER CALLING CTR, I WAS ASKED IDENTIFICATION INFO, WHICH I ANSWERED. THEN THEY TOLD ME I VIOLATED ZZZ1 EXTENDED AIRSPACE. I DID NOT REALIZE ZZZ1 HAD EXTENDED AIRSPACE. I PROBABLY SHOULD HAVE CALLED FSS, BUT IT WAS SUCH A NICE DAY, I DIDN'T REALLY FEEL IT WAS NECESSARY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.