  This paper presents the 2nd place solution to the Google Landmark Retrieval
2021 Competition on Kaggle. The solution is based on a baseline with training
tricks from person re-identification, a continent-aware sampling strategy is
presented to select training images according to their country tags and a
Landmark-Country aware reranking is proposed for the retrieval task. With these
contributions, we achieve 0.52995 mAP@100 on private leaderboard. Code
available at
https://github.com/WesleyZhang1991/Google_Landmark_Retrieval_2021_2nd_Place_Solution
