envelope but most lost [cf. @hwa03; @you06]. Detailed observations have revealed that the explosion of Cas A was turbulent and asymmetric and that the ejecta is now interacting with a clumpy circumstellar wind [see @hwa04; @che03 and references therein]. However, very little is known about the explosion and the interaction of the 1620(?) yr-old 11p2 despite its close similarity to Cas A.

In this paper, we report the discovery and detailed studies of and filaments in the SNR 11p2 using near-infrared (IR) imaging and spectroscopic observations. Although the recent mid-IR data obtained with the Spitzer Space Telescope show the presence of very faint wispy emission close to its SE boundary [@lee05; @rea06], our near-IR observations reveal much more prominent and extended features both at the boundary and interior of the remnant, which provide important clues on the origin and evolution of 11p2.

Observations
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We carried out near-IR imaging observations of the SNR G11.2-0.3 with Wide-field Infrared Camera (WIRC) on the Palomar 5-m Hale telescope using several narrow- and broad-band filters in 2003 June and 2005 August (Table 1). WIRC is equipped with a Rockwell Science Hawaii II HgCdTe 2K infrared focal plane array, covering $\sim 8.'5\times 8.'5$ field of 